1-s2.0-S0378112715002881-main

Effects of Forest Management on Productivity and Carbon Sequestration

Authors and Affiliations

• A. Noormets, North Carolina State University, Raleigh, USA

• D. Epron, Université de Lorraine, France

• J.C. Domec, North Carolina State University and University of Bordeaux

• S.G. McNulty, USDA Forest Service, Raleigh, USA

• T. Fox, Virginia Polytechnic Institute, USA

• G. Sun, USDA Forest Service, Raleigh, USA

• J.S. King, North Carolina State University

Article Information

• Received: December 30, 2014

• Revised: May 4, 2015

• Accepted: May 15, 2015

• Keywords: Belowground allocation, Carbon management, Harvest disturbance, Soil carbon sequestration, Trade-offs.

Abstract

• The review highlights the increasing importance of managed forests in meeting human needs for wood and ecosystem services.

• There is a critical need for quantitative assessments of functional changes in managed ecosystems compared to natural forests.

• Key areas of focus:

  • Long-term carbon sinks and climate change mitigation potential.

  • Contrasting carbon (C) exchange between managed and unmanaged forests.

• Managed forests are generally 50 years younger, contain 25% more coniferous stands, and store about 50% less C than unmanaged forests.

• Managed forests show similar gross primary productivity (GPP) and total net primary productivity (NPP) but allocate more assimilated C to aboveground pools, reducing allocation to fine roots.

• Long-term soil carbon sequestration potential is assessed, revealing managed forests may lose more C annually than they gain through detritus, influenced by climate factors and management practices like fertilization.

1. Background

• Increasing global population and land-use intensification elevate the role of managed forests (approximately 7% plantations and 57% recovering secondary forests).

• From 2000 to 2005, planted forest area expanded by 2% annually while total forest area declined by about 2% every decade.

2. Methods

2.1. Defining Managed Forests

• Managed forests are defined as those with active cultivation and preplanned rotation cycles.

2.2. Literature Review and Data Coverage

• Compilation of global datasets enhances understanding of productivity and C dynamics.

3. Results and Discussions

3.1. Key Differences in Carbon Cycles

• Managed forests are structurally younger and have significantly lower live and soil C stocks.

• Higher NPP and NEP in managed forests despite similar GPP suggests more efficient aboveground growth but higher respiratory costs.

4. Literature Review

4.1. Climate Effects on Productivity

• Climate change factors, especially CO2 concentration and temperature, critically impact forest physiology and C cycling.

4.2. Factors Altered by Management

• Nutrient Availability/Fertilization: Enhances productivity but alters allocation dynamics, affecting long-term C buildup in soil.

• Soil Disturbance: Harvesting activities cause carbon loss and influence soil carbon dynamics significantly.

• Stand Structural Disturbance and Age: Affect carbon allocation and overall ecosystem productivity.

5. Summary

• Management impacts on forest C exchange are closely linked to age-related structural changes and responses to environmental conditions.

• Managed forests tend to have increased aboveground productivity while potentially compromising soil C storage.

6. Final Remarks

• Optimal management practices must balance productivity and carbon sequestration potential. Future forestry must consider the holistic impacts of management strategies on carbon dynamics, particularly belowground.

Acknowledgements

• Supported by various grants and government institutions, including USDA and DOE.

Effects of Forest Management on Productivity and Carbon Sequestration

Authors and Affiliations

• A. Noormets - North Carolina State University, Raleigh, USA

• D. Epron - Université de Lorraine, France

• J.C. Domec - North Carolina State University and University of Bordeaux

• S.G. McNulty - USDA Forest Service, Raleigh, USA

• T. Fox - Virginia Polytechnic Institute, USA

• G. Sun - USDA Forest Service, Raleigh, USA

• J.S. King - North Carolina State University

Article Information

• Received: December 30, 2014

• Revised: May 4, 2015

• Accepted: May 15, 2015

• Keywords: Belowground allocation, Carbon management, Harvest disturbance, Soil carbon sequestration, Trade-offs.

Abstract

This review emphasizes the critical and increasing significance of managed forests in fulfilling human requirements for wood alongside broad ecosystem services. Managed forests represent a pivotal solution for maintaining a sustainable balance within the ecosystem, amid escalating demands from a growing global population. There exists a pressing need for comprehensive quantitative assessments to evaluate functional changes within managed ecosystems in contrast to their natural forest counterparts.

Key Areas of Focus:

• Long-term Carbon Sinks: Analyzes the potential of forests to act as sustainable carbon sinks, thus contributing significantly to climate change mitigation strategies.

• Contrasting Carbon Exchanges: Explores the differences in carbon (C) exchange processes between managed and unmanaged forests, highlighting variances in carbon storage and longevity.

Findings:Managed forests are generally observed to be approximately 50 years younger than unmanaged ones, harbor 25% more coniferous species, and sequester about 50% less carbon overall. Despite this, both types exhibit similar gross primary productivity (GPP) and overall net primary productivity (NPP). However, managed forests allocate a greater proportion of their assimilated carbon to aboveground biomass, thereby decreasing the proportion directed towards fine root systems.

Furthermore, the long-term potential for soil carbon sequestration is assessed; findings indicate that managed forests often experience annual carbon losses exceeding gains from detritus, influenced by variables such as climatic factors and management practices, including fertilization and harvesting.

1. Background

The interplay between an ever-increasing global population and heightened land-use intensification underscores the pivotal role of managed forests, composed of about 7% plantations and 57% recovering secondary forests. From 2000 to 2005, global data indicated a 2% annual increase in planted forest area, while the total forest area witnessed a decline of approximately 2% per decade.

2. Methods

2.1. Defining Managed Forests

Managed forests are characterized by active cultivation practices and pre-established rotation cycles designed to optimize yield and sustainability.

2.2. Literature Review and Data Coverage

A comprehensive aggregation of global datasets has been undertaken to enhance understanding regarding productivity levels and Carbon dynamics within these forests, facilitating nuanced discussions on management impacts.

3. Results and Discussions

3.1. Key Differences in Carbon Cycles

Structurally, managed forests are significantly younger and display lower levels of live foliage and soil carbon stocks. Increased net primary productivity (NPP) and net ecosystem productivity (NEP) in managed forests indicate a more efficient aboveground biomass growth, necessitating higher respiratory costs relative to unmanaged counterparts.

4. Literature Review

4.1. Climate Effects on Productivity

Factors associated with climate change, notably CO2 concentration fluctuations and temperature variations, pose critical implications for forest physiology and Carbon cycling processes.

4.2. Factors Altered by Management

• Nutrient Availability/Fertilization: Nutrient management augment productivity, yet can modify allocation dynamics which might hinder long-term soil carbon buildup.

• Soil Disturbance: Activities related to harvesting can yield significant carbon loss, disproportionately influencing soil carbon dynamics.

• Stand Structural Disturbance and Age: Variations in carbon allocation and overall ecosystem productivity are closely tied to the age of the stand and its structural characteristics.

5. Summary

The impact of management practices on forest carbon exchange is closely related to age-related structural shifts and their reactions to environmental conditions. Managed forests typically observe enhancements in aboveground productivity; however, this growth may come at the cost of reduced soil Carbon storage capacity, thus presenting a trade-off challenge.

6. Final Remarks

The pursuit of optimal management practices must strive to balance productivity against potential carbon sequestration benefits. Future forestry practices should consider the comprehensive impacts of management strategies on carbon dynamics, with a distinct emphasis on belowground carbon fluxes and storage mechanisms.

Acknowledgements

This research was made possible through support from various grants and government entities, including the USDA and DOE.